Theftproop electric light bulb



Nov. 9 1926. Re, 16,462

w. M. REECE ET m.

THEFTPROOF ELECTRIC LIGHT BULB Original Filed July 2 1923 (Eh wanton 9 Wm M. Reade, Carl E. Tom lz'uson UNITED-STATES PATENT OFFICE. g

WILBUB I. 3.33178, 01' ENTERPRISE, OREGON, AND CARL E. TOMLINSON, OI GHEHALIS, WASHINGTON, ASSIGNQBS TO KULP THEITPROOF LAMP COMPANY, OF CHIC AGO, ILLINOIS, A COBFOBATION OI ILLINOIS.

Reieeued N...-9, 192s. Re. 16,462

THEFTPBOOI' ELECTRIC-LIGHT B11128.

Original No. 1,517,584, dated December 2, 1924, Serial No. 653,948, filed July '26, 1928. Application for reissue filed December 23, 1925. Serial No. 76,978.

. Our invention relates to improvements in the outer side ofthe arm 8 and operative to electric bulbs and more particularly to force said arm inwardly to the position I means for locking the usual threaded shell shown in Fig. 4 when the stem 12 is turned of the bulb in a socket to prevent theft. to the proper extent. The other end of the I The object of the invention is to provide stem 12 is provided with an appropriate an extremely simple and inexpensive locking operating handle 14 and in the preferred means of the character set forth which can 'form of construction, the cam and handle only be released by breaking the bulb, thus are both formed by bending the ends of the 'placin it in a condition in which it cannot stem 12 substantially upon themselves, said 1 be used, even if stolen from the socket. stem being formed of a length of suitable J With the foregoing in view, the invention wire, as seen most clearly in Fig. 6. resides in the novel subject matter herein- To rotatably carry the stem 12, we prefer '05 after described and claimed, the description to provide a metal tube soldered or otherbeing supplemented by the accompanying wisesecured to the inner side of the shell 2 i6 drawing. and 1n order that air shall not enter the bulb' Figures 1 and 2 are side elevations partly around the stem, we provide said bulb with in section on lines 11 and 2-2 of Fig. 3. an internal seal 16 in the form. of a tube 70 a Figure 3 is a horizontal sectional view as which may be integral with the contracted indicated by lines 33 of Fig.- 1, showing the end of the bulb and with the side wall therelocking means in operative position. of as illustrated in Figs. 1 and 2, or may also Figure 4 is a duplicate of Fig. 3 with the be inte ally joined to the filament support exception that it illustrates the locking 17 as epicted in Fig. 5. In either case, 75 means released. 4 breakage of the bulb 1s necessary to permit Figure 5 is a detail sectional view showing rotation of the stem 12 and release of the a slightly difierent form of construction. detent 10 and hence theft of the bulb is pre- Figure 6 is a perspective view of the de vented. tent releasing stem and its handle and cam. In assembling the device, the detent 8' is 80 In the form of construction selected for soldered or otherwise secured in the shell 2, illustration in the present a plication, we above the insulator 7, the tube 15 is then make use of an electric light ulb 1 having soldered or otherwise secured to the inner theusual threadedshell 2 at one end for reside of the shell, the partition 5 is then in- 4 ception in the well known socket 4. A sheet serted, and the bulb is then downwardly inof fish skin paper or the like 5 extends across sorted into the shell, with the seal 16 passthe shell 4 to separate the bulb anchoring ing over the tube 15 and handle 14, and said 5 cement 6 from the contact-carrying insulatbulb is cemented in place, the current-coning end 7 of the shell 2, and in the space ducting connections being established in the thus provided is a locking device. This usual manner. 90 locking device is preferably in the form of It is not desired to limit the invention to l a spring arm 8 soldered or otherwise secured the details or examples herein described 40 at one end to the shell 2, while its otherend since it will be obvious to those skilled in the is formed with a pointed detent 10 passing art, after understanding the invention, that outwardly through an opening 11 in the various modifications and substitutions 95 shell, said detent being beveled to-a point as maybe made without de arting from the seen in Fig. 3, so that it willnot interfere scope of the invention, an we aim therefore 7 with threading of the shell into the'socket in the appended claims to cover all such 4, but will bite into the latter and preventmodificatlons. p unthreading of said shell, unless the arm 8 What is claimed as new and is desired to 1 is forced. inwardly to the position shown in besecure'd by Letters Patent of the United Fig. 4. States is: For releasing the arm 8 and detent 10, we 1. An electric light bulb having the usualhave provided a stem 12 parallel with the threaded shell, a locking device, within said axis of the shell, this stem being provided shell having a socket-engaging detent =ex-- on one end with a cam 13 contacting with tending outwardly therethrough to hold said shell against unthreading from the socket, a releasing key for said locking device confined within said bulb and accessible only by breaking the same, and a seal around said releasing key preventing entrance of air around the same.

2. An electric light bulb having the usual threaded shcll,-a locking device in said shell having a socket-engaging detent extending outwardly therethrough to hold said shell against unthreading from the socket, a stem extending into the bulb and having one end operatively associated with said locking device for releasing said detent when the stem is turned, the other end of said stem having a handle confined in the bulb, and a seal around said stem and handle preventing entrance of air around the same.

3. An electric light bulb having, the usual threaded shell, a locking device in said shell having a socket-engaging detent extending outwardly 't-herethrough to hold said shell against unthreading from the socket, a stem extending into the bulb and having on one fi end a cam engaging said locking device for releasing the same, the other end of said stem having a handle confined in the bulb, and a seal around said stem and handle preventing entrance of air around the same.

4. A structure as cam and handle being formed by bending the ends of said stem substantially upon themselves.

5. An electric usual threaded shell, a locking device within said shell having a socket-engaging detent extending outwardly therethrough to hold said shell against unthreading from the socket, an open-ended tube secured to the inner side of said shell and extendin into the bulb, a stem passing through said tube and operatively associated at one'end with said locking device, the other end of said stem having an operating handle, and a seal around said tube and handle preventing entrance of air around the same.

6. A theft-proof electric lamp for use with a conventional electrical receptacle comprising a glass bulb having a threaded shell fixed to the stem thereof as by cement, and locking means permanently incorporated in the lamp base and permitting the lamp to be freely threaded into the receptacle but effecting positive engagement with the conventional threaded receptacle shell for securing the lamp against removal upon attempted turning movement in a direction to remove the lamp. said locking means being normally covered by the bulb and receptacle parts when the lamp is in operative osition but having parts purposely'designe to be freely exposed and manipulated to release the locking means upon breaking away the bulb glass.

. 7. A theft-proof electric lamp for use specified in claim 3, said 1 light bulb, having the' detent member exfreely exposed and manipulated to release the etent member upon breaking away the bulb glass.

8. In combination, a frangible enclosure for electrical apparatus, a cylindrical shell contact fixed on said enclosure, said shell contact being provided with means for engaging a conventional electrical receptacle by turning movement, and locking means xed to said contact permitting the contact to be turned into a receptacle but having means for biting into the receptacle shell interior "wall when rotational force is exerted to turn the contact outwardly of the receptacle, said locking means being normaly covered by the enclosure and receptacle parts when in operative position but being releasable by a key member upon breaking away the frangible enclosure.

In combination, an electric lamp for use with a conventional electrical receptacle comprising a bulb member having permanently secured thereto a threaded shell to be received by the conventional threaded receptacle shell,anda locking means comprising a spring wire member extending substantially circumferentially along the wall of-the lamp shell with one end retained against movement in respect to the lamp and its other end protruding for positive enagement with a receptacle when rotational orce is exerted to turn the lamp outwardly of a receptacle, said locking means being normally covered and inaccessible when the lamp is in operative position in a receptacle but being purposely designed to be freely exposed and releasable upon breaking away the bulb glass.

10. An electric lamp comprising a bulb having the usual threaded shell, a locking device within said shell having a socket engaging detent extending outwardly therethrough to hold said shell against unthreading from the socket, said detent being formed with an arcuate shaped spring arm extending substantially along the wall of said shell, one end of said arm being fixed against movement with respect to the bulb and its other end being sharpened for extending into positive engagement with the socket, and a releasing portion of said locking device confined within the lamp, the bulb being sealed adjacent said releasing portion for preventing entrance of air around the same, said releasing portion being accessible only upon breaking the adjacent sealed portion ofthe bulb.

11. A theft-proof electric lamp for use with a conventional electrical receptacle comprising a bulb member having a threaded contact shell permanently secured against rotation and longitudinal movement in respect thereto and shaped to be received by a conventional form of fixed threaded receptacle shell, and locking means forming a permanent part of the lamp and having a beveled spring pressed detent capable of substantially penetrating the metal wall of the receptacle shell contact and extending from said threaded shell of the lamp in a direction whereby the lamp may be freely inserted into the receptacle but upon exerting force to turn the lamp out of the receptacle said detent will be held fast in positive engagement with the receptacle shell wall and secure the lamp against removal.

12. A theft-proof electric lamp for use with a conventional electrical receptacle comprising a bulb member having a threaded shell contact permanently fixed against rotation in respect thereto and shaped to be received by the conventional threaded receptacle shell, and a wire detent member having a spring arm extending substantially circumferentially along the wall of the lamp shell with one end made fast to the lamp shell and its other end pointed and normally forced outwardly by said spring arm for biting into positive engagement with a fixed receptacle shell when rotational force is exerted to turn the lamp outwardly of the receptacle.

' 13. In a theft-proof lam of the type 'described, a bulb member, an a threaded shell contact mounted thereon and provided with key engaging means for facilitating release of the contact from a receptacle, said key engaging means being positioned to be accessible, when the contact is in a receptacle, only from within the base of thelamp upon breakage of the bulb.

14. A theft-proof replaceable electrical device comprising a frangible enclosure having delicate electrical apparatus therein, a cylindrical threaded shell supporting contact permanently made fast directly to the enclosure for engaging the conventional form of threaded electrical receptacle, and a detent member comprising a spring arm with one end made fast to the shell and its other end pointed and normally forced outwardly by said spring arm for effecting substantial penetration of the adjacent concave interior wall surface of the conventional receptacle when rotational force is exerted to WILBUR M. REECE. CARL E. TOMLINSON. 

